1. FIELD OF THE INVENTION
The present invention pertains generally to the field of personal footwear and more particularly relates to the manufacture of biomechanically adapted custom footwear.
2. STATE OF THE PRIOR ART
Human locomotion involves a complex but specific sequence of movements of the foot during which the foot is subject to great pressures and stresses, even in normal standing and walking activities. The human foot comprises a large number of bones and a multitude of joints all of which must cooperate closely and in correct relationship during such activities and dysfunctionate, frequently painful anomalies of the foot anatomy are common. Orthopedic medicine, directed to prevention and correction of such anomalies, is well developed and supportive footwear has long been available for alleviating or preventing biomechanical difficulties of the foot.
The greatest number of commercially manufactured footwear is not constructed to cooperate with the normal, natural biomechanics of the foot. A small portion of commercial footwear does incorporate some biomechanical considerations in its design but mass manufacture necessitates that the footwear be fitted to some theoretically derived average foot and consequently does not address the myriad anatomical variations and peculiarities encountered between one individual and the next. Attempts at biomechanical improvements in commercial footwear have included "insoles" for cushioning and/or arch support, such as are shown for example in Mosher U.S. Pat. No. 4,232,457. Other orthopedically corrective elements incorporated into footwear are shown in Schenihaus et al. U.S. Pat. No. 4,446,633 and Marsh U.S. Pat. No. 4,453,322. Resilient removable inserts have been introduced to provide improved protection against heel strike, particularly in sport shoes. Still other cushioning elements have been devised using water, gels, and other fluids capable of conforming to and supporting the foot in the shoe. Self-injectable gels and other compounds intended to take on the shape of an individual foot and set permanently in that shape are available, particularly in connection with ski boots and the like. These devices however are accommodative in nature, rather than biomechanically adaptive, in that the shoe conforms to and fits the foot but does not produce any biomechanical improvements. These devices in any event are not very popular on the consumer market. Pre-made arch supports are also available and typically consist of pre-formed foam inserts which do improve the bio-mechanics of the shoe, but do not provide sufficient biomechanical correction for many individuals and are therefore of limited value.
A great deal of attention has been directed in recent years to biomechanical improvements in sporting and exercise footwear. Many of the techniques and approaches which have been traditionally thought of as corrective in nature have been more recently adopted by manufacturers of sporting shoes, and the use of biomechanically corrective shoes is no longer viewed as a stigma, but rather a status symbol. Such footwear, however, may also be generally categorized as adaptive footwear, i.e. footwear designed to adapt to the shape of the wearer's foot, rather than biomechanically correct supportive footwear. Various approaches have been used in constructing adaptive footwear. The sole material may be selected to have a suitable durometer rating, i.e. resilience, so as to better absorb shock. This feature may be combined with a shaped sole, such as a sole curved to the shape of some "average" foot. The bio-mechanics of such adaptive footwear are indeed improved and such footwear is popular and beneficial. The drawback lies in the fact that the footwear is mass produced and not sufficiently tailored to individual needs.
At the opposite extreme, orthotic inserts are available for correcting specific, individual biomechanical foot problems. Orthotic inserts are fully customized items prepared in accordance with the medical prescription of a podiatrist following examination and evaluation of the particular patient's foot bio-mechanics. These inserts are only available by prescription from an orthopedic physician, podiatrist or other medical doctor for providing lift and support to affected portions of the foot and thereby to biomechanically correct a specific diagnosed problem. Orthotic inserts are intended for use with ordinary, commercially mass produced footwear and as a rule are constructed to support only the arch and sometimes the heel of the foot. Orthotic inserts do not extend to the toes of the foot. Custom made orthotics are expensive and may not fit all types of commercially available footwear.
In spite of these and other efforts, spanning many decades, aimed at providing biomechanically correct footwear, and notwithstanding the availability of both mass produced and custom orthotic devices and footwear, there is a continuing need for footwear which is biomechanically custom fitted to the individual yet available at reasonable cost without prescription.